P. Fermo

Heterogeneous distribution of metal nanocrystals in glazes of historical pottery

It has been recently shown that lustre decoration of medieval and renaissance pottery consists of silver and copper nanocrystals, dispersed within the glassy matrix of the ceramic glaze. Lustre surfaces show peculiar optical effects such as metallic reflection and iridescence. In many cases, lustre appears overlapped to colored drawings. Here we report the findings of a study on glazes, pigments and lustre of several shards belonging to Deruta and Gubbio pottery of XVI century. The components of glazes and pigments have been identified. Lustre is confirmed to be characterised by silver and copper metal nanocrystals inhomogeneously dispersed in the glassy matrix of the glaze. In the case of lustre overlapped to colored decorations, we found two contradictory cases. The first consists of a lustre surface successfully applied over a blue smalt geometrical drawing. The second consists of a lustre surface, unsuccessfully applied over a yellow lead-antimonate pigment. The yellow pigment hinders the formation of lustre and removes crystals of tin dioxide, normally present in the glaze as opacifier.

PM10 source apportionment in Milan (Italy) using time-resolved data

In this work Positive Matrix Factorization (PMF) was applied to 4-hour resolved PM10 data collected in Milan (Italy) during summer and winter 2006. PM10 characterisation included elements (Mg-Pb), main inorganic ions (NH(4)(+), NO(3)(-), SO(4)(2-)), levoglucosan and its isomers (mannosan and galactosan), and organic and elemental carbon (OC and EC). PMF resolved seven factors that were assigned to construction works, re-suspended dust, secondary sulphate, traffic, industry, secondary nitrate, and wood burning. Multi Linear Regression was applied to obtain the PM10 source apportionment. The 4-hour temporal resolution allowed the estimation of the factor contributions during peculiar episodes, which would have not been detected with the traditional 24-hour sampling strategy.

Characterization of ancient magnesian mortars coming from northern Italy

Abstract Different ancient mortar samples were analyzed to characterize their binder fraction. Thermal analyses (TG, DSC) proved to be very useful in the identification of three different species of lime composed of: (a) only calcite; (b) calcite and magnesite; (c) calcite, hydromagnesite and magnesite. The hydromagnesite is well identified in the DSC curve showing the peaks corresponding to the three-step thermal decomposition. Also the same mineral was detected by FTIR and/or micro-FTIR analyses, depending on its amount in the binder fraction of the mortar. Actually, the two absorption peaks characteristic of the hydromagnesite were often hidden by the wider peaks due to the asymmetric stretching of the carbonate ion, observed for the calcite and magnesite.

A simplified method for levoglucosan quantification in wintertime atmospheric particulate matter by high performance anion-exchange chromatography coupled with pulsed amperometric detection

Levoglucosan, a tracer for the assessment of the biomass burning contribution to atmospheric particulate matter (PM) concentrations, was determined by means of high-performance anion-exchange chromatography (HPAEC) with pulsed amperometric detection (PAD). In this work we propose a modification in the instrumental set-up aiming at an improvement in the detector response by adding NaOH after chromatographic separation to increase the pH. The comparison between this technique and the gas chromatography/mass spectrometry (GC/MS) method commonly used showed good agreement. Repeatability is 4.8% RSD, limits of detection for pevoglucosan, mannosan and galactosan are in the range 0.001–0.002 µg mL−1 in solution, corresponding to 3–4 ng m−3 for 24 m3 of air sampled. PM10 samples were characterised for levoglucosan and for organic and elemental carbon contents. The preliminary results reported here for five sites in the Lombardy region (Northern Italy) are, as far as we know, the first data on levoglucosan contribution to OC in Italy. The levoglucosan concentrations observed in Lombardy vary in the range 173–963 ng m−3 with an average levoglucosan-C to OC ratio ranging from 1.5% to 2.5%.

A new approach for archaeological ceramics analysis using total reflection X-ray fluorescence spectrometry

Abstract The purpose of this study is to investigate the use of a new quantitative analysis method in case total reflection X-ray fluorescence (TXRF) is applied to archaeological ceramics. This method is alternative to and simpler than traditional TXRF quantitative analysis or typical techniques of elemental analysis such as atomic emission and absorption spectrometry (AES and AAS) which implies the chemical digestion of the sample. A new procedure which allows to obtain an homogeneous sample has been successfully applied. This way it was possible to obtain quantitative results for the elements present in the sedimentation obtained from a suspension prepared with the ceramic sample, by resorting to addition of an internal standard. The archaeological ceramic shards have been also chemically digested and analyzed by inductively coupled plasma-atomic emission spectrometry, AES with flame atomization and electrothermal atomic absorption spectrometry. The quantitative data obtained by means of both TXRF, AAS and AES were compared and worked out by multivariate statistical techniques, such as principal components analysis and hierarchical cluster analysis in order to achieve information concerning pottery provenance.

Optimisation of analytical procedures for the quantification of ionic and carbonaceous fractions in the atmospheric aerosol and applications to ambient samples

In the last decade, our research group set up and optimised analytical techniques for the characterisation of the major components of atmospheric aerosol (i.e. secondary inorganic ions and carbonaceous material) and source markers (e.g. levoglucosan, carbonates). In this study, we present a complete overview on the most problematic aspects that can be encountered during the quantification of the two main components of aerosol, i.e. the ionic and carbonaceous fractions. More in detail, different liquid chromatographic approaches were set up for main ions and anhydrosugars determination. Quality assurance procedures (i.e. tests on data reliability) were applied during the set-up phase and they are presented in this work. As regards the carbonaceous component characterisation, two evolved gas analysis techniques were set up and applied: the thermogravimetric technique coupled to the Fourier transformed infrared spectroscopy (TGA/FTIR) and the thermal–optical transmittance method (TOT). A suitable protocol for organic and elemental carbon separation was set up for the TGA/FTIR system and a comparison with the results obtained by the TOT method was carried out. Studies on the impact of filter load, field blanks, and sample composition on OC/EC quantification by the TOT method were performed. Moreover, approaches for carbonate carbon quantification on different kinds of filters were developed. It was demonstrated that this approach allows to reach the ionic balance in samples impacted by carbonate compounds. The optimised methods have been applied for the analysis of thousands of PM filters allowing the obtainment of reliable results.

The use of small angle X-ray scattering (SAXS) for the characterisation of lustre surfaces in Renaissance majolica

Abstract In this work some Renaissance lustre decorated ceramics have been examined. Our attention was directed to lustre which is a thin decorative metallic film applied on the surfaces of previously glazed ancient pottery. Some 16th century lustre ceramics shards from Deruta, Umbria (Italy) have been analysed by small angle X-ray scattering (SAXS) in order to characterise the dimension of the metal nanocrystals forming the thin lustre layer. This technique appeared to be a powerful tool to characterise lustre films nanostructure and may be successfully used for this purpose together with transmission electron microscopy (TEM). Furthermore, SAXS measurements are extremely suitable for the determination of polydispersity and average interparticle distance. The lustre surfaces have been also analysed by scanning electron microscopy plus X-ray energy dispersive spectrometry (SEM–EDX) in order to identify the metals present (silver, copper or both of them) and to establish copper/silver ratios. From the comparison between SAXS results and compositional data, it was possible to conclude that copper particles are smaller than the silver ones. We have evidenced how the microtexture as well as the chemical composition of the lustre layers are responsible for the gold or red colour typical of the lustre films.

Ionic profile of honey as a potential indicator of botanical origin and global environmental pollution

Aim of this study was to determine by Ion Chromatography ions (Na(+), Ca(++), Mg(++), NH4(+), Cl(-), Br(-), SO4(2-), NO3(-), PO4(3-)) in honeys (honeydew and floral nectar honeys) from different Italian Regions and from countries of the Western Balkan area. The compositional data were processed by multivariate analysis (PCA and HCA). Arboreal honeydew honeys from the Western Balkans had higher concentrations (from two to three times) of some environmental pollutants (Br(-), SO4(2-) and PO4(3-) contents), due to industrial and agricultural activities, than those from Italian regions. The cationic profiles were very similar in both groups. Multivariate analysis indicated a clear difference between nectar honeys and arboreal/honeydew honeys (recognition of the botanical origin). These findings point to the potential of ionic constituents of honey as indicators of environmental pollution, botanical origin and authenticity.

Size-Resolved Identification, Characterization, and Quantification of Primary Biological Organic Aerosol at a European Rural Site

Primary biological organic aerosols (PBOA) represent a major component of the coarse organic matter (OMCOARSE, aerodynamic diameter > 2.5 μm). Although this fraction affects human health and the climate, its quantification and chemical characterization currently remain elusive. We present the first quantification of the entire PBOACOARSE mass and its main sources by analyzing size-segregated filter samples collected during the summer and winter at the rural site of Payerne (Switzerland), representing a continental Europe background environment. The size-segregated water-soluble OM was analyzed by a newly developed offline aerosol mass spectrometric technique (AMS). Collected spectra were analyzed by three-dimensional positive matrix factorization (3D-PMF), showing that PBOA represented the main OMCOARSE source during summer and its contribution to PM10 was comparable to that of secondary organic aerosol. We found substantial cellulose contributions to OMCOARSE, which in combination with gas chromatography mass spectrometry molecular markers quantification, underlined the predominance of plant debris. Quantitative polymerase chain reaction (qPCR) analysis instead revealed that the sum of bacterial and fungal spores mass represented only a minor OMCOARSE fraction (<0.1%). X-ray photoelectron spectroscopic (XPS) analysis of C and N binding energies throughout the size fractions revealed an organic N increase in the PM10 compared to PM1 consistent with AMS observations.

Iron doped zirconium silicate prepared by a sol–gel procedure. The effect of the reaction conditions on the structure, morphology and optical properties of the powders

A sol–gel reaction starting from Si and Zr alkoxides, in water–ethanol mixtures, was employed to obtain iron doped zirconium silicate powders (zircon). The speciation of the ferric salt to be added to the starting mixture was varied, the anion matching, in each case, the anionic partner of the acid catalysing the gel polycondensation reaction. The effects of varying the time of the two separate hydrolysis steps leading to the gel formation were investigated. The products of the sol–gel reaction were calcined in the range 800–1300 °C. The specific surface areas of all the samples were measured by the BET method; X-ray diffractograms and diffuse reflectance spectra were obtained and analysed for all the calcined powders. Results from the structural, morphological and spectral characterisations were examined and compared to produce a consistent picture of the key factors leading to the formation, growth, aggregation and optical properties of the reaction products.